Sparking plug.



PATBNTED JULY 7, 1903.

} J. (1.,ANDERSON.

SPARKING PLUG. urmognon nun JULY 31. 1901.

H0 MODEL.

UNITED "S'rAT s Patented Jul 7, 1903. v PATENT OFFICE.

JAMES C. ANDERSON, F HIGHLAND PARK, ILLINQIS.

sPA Kmo PLUG.

SPECIFICATION forming part-of Letters Patent No. 732,812, dated July .7, 1908.

Application filed July 31, 1901- Serlal No. 70,376. (No model.) 7

same.

My invention relates to certain new and. useful improvements in sparkiugplngs for.

gas-engines and in the method of making the same.

In the use of sparking plugs in gas-engines the conditions are such that many diificulties are encountered in making them effective and durable. r

It is necessary that the connection between the plug and the explosion-chamber of the engine should be absolutely air-tight to prevent any escape of the commingled compressed air and hydrocarbon,'and it is also -.important in the highest degree that complete insulation should be made. In making the air-tight joint two difliculties are experienced, to Wit: It the plug be screwed up tightly, such action tends to crack or break the insulating material; and if the joint be made tight by the use of a packing the material-such, for instance, as asbestos, which is a non-conductor of comparatively poor officiency-is liable to absorb the oil or greases from the explosion-chamber, which tends to short-circuit the current. I

It has been proposed to use porcelain and bodies other than glass as the insulating material in sparking plugs; but the difficulty or impossibility of making a tight joint directly between the porcelain or other bodies and its surrounding shell or casehas rendered it necessary to employ apacking, with the consequent disadvantages hereinbefore referred to. Another objection to the use of such bodies and in the ordinary manner has been the liability of its fracture or of its being blown out of its seat and packing by the force of the explosions recurring in the explosivechambe'r. It is desirable, however, that glass should be used, because of its high quality of insulation and for the reason that it is important that the sparking plug should be of small'or circumscribed proportions, a plug 'with glass insulation and of small dimensions being more eifective than a much larger plug using other insulating material.

My invention has for its object to provide a sparking plug with glass, insulation and having such characteristics, as the result of the method of its manufacture, that it may be screwed up tightly in its seat to make an air-tight joint without the use of any packing calculated to short-circuit the current and.

not liable to the fracture of the insulatingbody or of its being blown out by the repeated discharges within the explosion-chamber.

With these ends in view my invention consists, broadly, of a sparking plug embodying in its organization a steel casing threaded for proper securement within the wall of theexplosion-ehamber of an engine, a central conducting core or pole, and an insulating-body appreciate all of its ad vantages, I will proceed I to describe its construction and the'method of making the same, referring by letters to the accompanying drawings, in which.-

Figure 1 represents the several parts employed in making up the finished article. Fig. 7

2 represents in section the several parts shown in Fig. 1 in assembled relation between a pair of dies prior to being subjected to compression between such dies. Fig. 3 is a perspective view of the plug in its-completed condition, and Fig. 4 is a longitudinal central secshown in elevation.

Similar letters of reference indicate like parts'in the several figures of the drawings. A is a cylinder or ring of steel cored out centrally, as shown at B, and adapted to receive a loosely-fitting tube of glass 0, which 'tion of the same with the central core or pole lOO in turn is provided with a central longitudinal passage D, adapted to receive the reduced portion E of a metal core F, which constitutes the electric pole of the finished plug.

The glass tube bears such relationin its dimensions to the cylindcr A and the recontact with the cylinder or ring A and the portion E of the core F, as clearly shown at Fig. 4.

When the several parts A, (J, and F are all assembled, as shown at- Fig. 2, and disks of -mica H are located as shown, they are subjected to heat of such a degree as to render the glass tube 0 viscid'or capable of compression, and they are then subjected to pressure between dies G in any suitable press, the heatof the metal constituting the cylinder or ,ringA and the core or pole F and the heatand condition of the glass tube 0 are such that the surplus ofglass extending above and below the ends of the ring A is taken-up by the movement of the body of the tube into close contact with the cylinder and core, as heretofore described, and an intimate and close cohesion or union, which I have heretofore denominated as a quasi weld, is made between the glass and the metal.

The mica disks II, through which the reduced portion E of the core F passes, constitute shields to prevent the glass 0 and ring A from attaching themselves to the faces of the dies G, and after the parts have remained for a short time between the dies the latter are separated and the product is removed. When cold and in condition to do so, the rough prodnet is machined into the condition shown at Figs. 3 and 4, the projecting end of the core or pole F being threaded and adaptedto receive binding-nuts I I, the upperorouter portion of the cylinder or ring A being formed into a nut-head J and flange K, while the lower and reduced portion is threaded, as shown at L, Fig. 4, so that by the use of a wrench upon the nut-head J the plug may be secured tightly within a suitably-threaded seat in the wall of the explosiomchamber of an engine wherein the spark is to be made by the current passing from the sparking bat.-

tery through suitable connections between it and the binding-nuts I I in an obvious or wellknown manner.

The completed plug, as shown, is designed to be used in pairs disposed in oppositesides -of the explosion-chamber in such manner as to create an are within which the spark is made.

In subjecting the several parts of my improved plug to the action of heat, as described, the characteristics and properties of the metal and glass are such that in the cooling and necessarily contraotive action thereof, which capable of compression, I am enabled to compress the said insulating material fiush with the ends of the ring or casing and to thus completely house the insulating material and to protect it from the disintegrating or moving effect otherwise produced by the recurring explosions or resulting from the changes of temperature.

\Vhile as I have practiced my invention I prefer to use glass as the insulating material and have been'enabled to produce a substantially perfectattachment or quasi weld of the glass and the metal parts of the plug, I do not wish to be confined to the use of glass or to any particular extent of welding action, for I may use any other suitable insulating-body which is capable of being put into a viscid or compressible condition and may make the necessary close or removable relation between the several parts. by suitably roughening or grooving the metal portions and com pressing the insulating material into such roughened or grooved parts to constitute binding or keys, the generic feature of my invention resting in the broad idea, as stated, of subjecting the several parts of the plugto the action of heat and pressure to make close mechanical contact between the metal portions and the insulating material and to 'completely house the insulating material throughout its entire length. 7

Having described the construction of my improved plug and its characteristics resulting from the method of manufacture, what I claim as new, and desire to secure by Letters Patent, is

1. A sparking plug for gas-engines composed of an outer metal ring or casing adapted to be fitted within a chamber of a gas-engine, an interior metal core or pole, and a body of insulating material surrounding the core orpole and between it and the ring or casing'and in actual and mechanically constant and fixed union and weld with said core or pole and easing, substantially as and for the purposes set forth.

" 2. As a new article of manufacture asparking plug composed of an outer metal ring or casing adapted to be secured within the explosion-chamber of a gas-engine, an interior metal core or pole, and an insulating-body of glass between the ring or casi or pole, and in permanent; and fixed union and weld with said casing and core or pole,

substantially as set forth. 3. The method herein described for man u- IIO i'acturing sparking plugs, which consists in assembling a metal ring or casing, a metal core or pole, insulating material between the ring or casing and the core or pole, subjecting the insulating material to heat to produce a viscid or compressible condition of the same, and finally subjecting the insulating material to pressure and forcing it into fixedi and ('onstant union and Weld with the metal portions, substantially as and for the purposes to set forth.

In testimony whereof I aifix my signature in presence of two witnesses.

JAMES C. ANDERSON.

Witnesses:

D. G. STUART, Mo. 3'. HARROWE 

